Automobile brake tester



NOV. 16, 1937. J SHROYER 2,098,979

AUTOMOBILE BRAKE TESTER Filed April 17, 1936 2 Sheets-Sheefl FE 2UP(/ACOB L. (T /e0 r52.

Nov. 16, 1937. J SHROYER 2,098,979

AUTOMOB ILE BRAKE TES TER Filed April 17, 1936 2 Sheets-Sheet 2 wan/1wPatented Nov. 16, 1937 STATES PATENT OFFHZE '7 Claims.

The present invention relates to an automobile rake tester, and moreparticularly to a mechanism or apparatus capable of indicating equal ormaladjustment of the brakes of two wheels of a pair of automobilewheels, so that in the event of maladjustment proper adjustment may bemade.

In connection with the use of four wheel brakes, it is sometimes thepractice to adjust the brakes so that the braking effect applied to thefront wheels is diiferent from, preferably less than, the braking effectapplied to the rear wheels.

The present invention has for an object the provision of a simple,readily portable apparatus or mechanism which may be put down anywherefor use for testing the brake adjustments of both wheels of a pair ofautomobile Wheels, for exampie, both front wheels of an automobile, aswell as both rear wheels.

Another object of the present invention is to provide a brake testingapparatus whereby any differential brake adjustment of the brakes ofboth wheels of the pair of wheels may be readily ascertained.

A further object of the present invention is to provide a brake testingapparatus wherein the resistive effect necessary to move a platform onwhich the braked wheels rest in such manner as to proportionatelyrepresent the braking effect of the wheels in service.

The above other and further objects of the present invention will beapparent from the following description and the accompanying drawmgs.

An embodiment of the present invention is illustrated in theaccompanying drawings and the views thereof are as follows:

Figure l is a top plan view of a brake testing apparatus constructed inaccordance with the present invention and showing in dotted. linescertain of the details of the apparatus.

Figure 2 is a plan view of the base plate of the apparatus of thepresent invention, and a fragmental view, with parts in section, of aremovable platform, and showing the preferred means for indicatingmovement of the platform under test conditions.

Figure 3 is a vertical sectional view taken substantially in the planeof line IIL-III of Fig. 1 and showing certain parts in elevation.

Figure 4 is an enlarged vertical sectional view taken on the planeindicated by line IVIV of Fig. 1.

Figure 5 is a fragmental elevational view, with parts in section, of themanually operable means for moving the test platform, showing the partsin normal position, and

Figure 6 is a fragmental elevational view of the manually operable meansfor moving the platform where resistance to movement is offered by thebraked wheels, and illustrating the indicating means for showing theamount of resistive effects offered by the platform against movement bythe moving means, as governed by the braked wheels on the test platform.

The drawings will now be explained.

The illustrated form of the invention includes a base plate I withupturned side walls 2 and 2a extending lengthwise of the base, and towhich are welded or otherwise secured ramps 3 and 4 whereby anautomobile may enter and leave the testing apparatus.

The flanges of the base plate l define a channel within which moves anelongated platform A which is a platform supporting the two wheels of apair of automobile wheels undergoing tests. The length of the platform Ais slightly less than the length of the base plate l while the width ofthe platform A is considerably less than the Width of the base betweenits flanges so that the platform may have room for movement between theramps.

Suitably secured to or integrally formed with the base plate I, arerunners 5 which directly reston a floor or foundation underneath theapparatus, and underlying the automobile wheels when on the platform.

Carried by the under side of the platform A are sets of rollers 6secured by means of suitable pins to bearing members i, which in turnare suitably fastened to the under side of the platform. There is a setof such rollers near one end of the platform and a similar set near theother end of the platform, as may be readily observed in Fig. 1, and sodisposed as to underlie the automobile wheels on the platform andoverlie the runners 5.

Suitably secured to the under side of the platform A, at substantiallymid-length thereof, are two transversely extending and lengthwise spacedangle bars 8 which between them form a guide 9 for a roller it]supported on the plate I by a vertical pivot II. The purpose of theroller l0 and the guide members 8 is to permit movement of the platformbetween the ramps without endwise displacement of the platform inservice. Furthermore, the roller I0 serves as a pivot in event that theplatform is oscillated by reason of unequal brake adjustment of .thewheels being testedv extending angle members I 2 which serve asabutments for springs l3 interposed between the abutments l2 and theflange i l which extends downwardly from the platform A alongside thewall 2 of the base plate at the exit side of the apparatus. Thesprings l3 therefore tend to normally maintain the platform A with its flange l4against the adjacent wall 2 of the base plate, which is the normal orinoperative position of the platform, as may be observed in Figs. 1, 2and 3. The springs also function to. reduce the sensitivity of theapparatus in practical operation.

Without them, the equalization of the brakes could not be achieved.

At one end of the base plate l is etched or otherwise fashioned a scaleit? having suitable markings thereon to represent the extent of movementor displacement of the platform in service.

For swinging over the scale 35, two pointers l6 and H are provided.These pointers are connected to formed parts of hub-s l8 and i9respectively which are coaxially pivoted to a pin 20, suitably securedin the base plate I. The pointers are preferably arranged, one above theother, as may be readily observed in Fig. 4.

For swinging the lower pointer It, a cable 2| is secured at one end, asat 22, adjacent the end of the platform A remote from the scale it. Thiscable passes around guide rollers 23 and 24 and is connected to the hub53 of the pointer It so that any deflection of the remote end of theplatform will be readily effective to swing the pointer Hi.

The pointer fl is oscillated about its pivot by means of a cable or cord25 connected at one end, as at 23 to the adjacent end of the platform,

and to the hub I 9 of the upper pointer IT with the result that anydeflection of the platform will cause corresponding movement of thepointer I1.

In order to move the platform A, after a pair of automobile wheels havemounted it, the brakes are applied to the wheels, and the platformmanually moved by the following instrumentalities:

Along the front flange 2a of the base plate I,

which is the lower flange as observed in Fig. 1

and the lefthand flange as observed in Fig. 3, are bearing lugs 2-? forreceiving an oscillatable shaft 28 which is parallel to the length ofthe platform. Suitably pivotally connected to the platform A, atsubstantially its mid-length, is a hooded member 23 into which projectsone end of the shaft 28. The hood is fashioned with a curvilinearportion 33 against which a roller 3| moves under certain conditions.

Secured to the extremity of the shaft 28 within the hooded member 23 isan arm 32 carrying the roller 3i at an end, the other end being suitablyconnected to the shaft. Theshaft 28 has its other end projectingslightly outwardly of the end of the plate I, and outwardly of theadjacent ramp 3 as may be observed in Fig. l, to afford space for entryof an automobile onto the testing apparatus, and adjacent the end of thebase I carrying the scale l5.

Outwardly of the adjacent ramp 3, an upstanding member or levermember 33is secured to the shaft by means of a collar 35 fastened to the shaft bya key 35, thus the lever 33 is connected to the shaft'for oscillatingit. A supplemental member or lever 36 extends along the lever 33 andprojects above it with its upper end serving as a handle for oscillatingthe shaft 28. At its lower end, the supplemental lever St is connectedto the lever 33 by means of a bolt 3'? which passes Secured to the baseplate I are longitudinally through suitable apertures 38 in the lever 33and enlarged apertures 39 in'the supplemental lever 36 to allow play ofthe lever 36 on the bolt whereby the levers 36 and 33 may be angularlymoved relatively to each other.

Attached to the upper extremity of the lever 33 is a bar or gauge member40 carrying certain indicia M on it.

A yoke 42 is rotatively connected to the supplemental lever 35 by a pin43 with the other extremity of the yoke forming a bridge 42a which isapertured to receive the gauge member 49. Surrounding the gauge memberAll between the lever 33 and the end of the yoke 42 is a spring 44 whichis adapted to maintain the levers 33 and 36 in closely adjacentposition, such as shown in Fig. 5, in which position the gaugecooperates with the bridge end 42a of the yoke 42 as an index membentorepresent Zero on the scale.

Figs. 1 to 5 inclusive show the apparatus in normal or inoperativeposition which is that oc-' cupied by all of the parts prior to a test.

The two wheels of a pair of automobile wheels are tested in thefollowing manner: The automobile is driven onto the test apparatus inthe direction of the arrows shown in Figs- 1 and 3, that is, from thebottom of the sheet of Fig. 1

and from the left of Fig. 3, up the ramp 3 onto the platform A whereuponthe vehicle is stopped with the two wheels of a pair resting on theplatform. The brakes are then applied to the wheels. The test operatorthen grasps the lever 36 and swings it to the right as viewed in Figs. 5and 6 and to the left as viewed in'Fig. 3, to move the platform Adownwardly as viewed in Figs. 1 and 2, and to the leftas viewed in Fig.3, thus moving the platform or ground underneath the braked wheels, asdistinguished from moving the braked wheels over the ground.

If the brakes on the wheels being tested are equally effective, theplatform A will then move in a direction perpendicular to its length,such extent of movement being indicated by movement of the pointers l6and ll over the scale with both pointers in register, as with equalbrake adjustment there is no tendency to oscillate the platform.

If, however, the brakes of the wheels being tested are unequallyadjusted, then manipulation of the lever 36 will cause oscillation ofthe platform. 3

Suppose oscillation of the platform A would cause the righthand endthereof, as viewed in Figs. 1 and 2, to be moved to a greater extentthan the lefthand end. In such event the pointer it would be moved agreater distance over the scale !5 than would the pointer ll, thedifference of the positions of the 'pointersover the scale representingthe maladjustment of the brakes. The test operator then would adjust thebrakes, return the platform A to normal position, which would beaccomplished by releasing the brakes of the wheels then return the lever36 to normal position whereupon the springs l3 will automaticallyrestore the platform to normal position. The brakes are again appliedand the test repeated until the brakes are equalized, which would beshown by movement of the platform A perpendicular to its length withoutany oscillation,

Whenever the lever 36 is grasped to move the platform A, and there isany resistance to move ment of the platform created by the braked wheelson it, the lever 36 will move away from the lever 33, as viewed in Fig.6, thus moving the yoke 42 along the gauge 49 against the tension of thespring M to, say, the position shown in Fig. 6. In this position, thegraduation 5 may be observed, which represents 500 pounds braking effortof the brakes as then set.

Whenever the platform A is moved perpendicular to its length, and thereis any resistive effort to such movement by the braked wheels, theindication of such effect may be observed by the projection of the gaugeAll, through the bridge end lfa of the yoke 4'2. If the operator of thetesting apparatus knows the proper resistive effect for any car, he canthen adjust the brakes to secure such efiect, if the reading on thegauge 4E3 is not the proper one.

Carrying out a test on the present apparatus, the first thing done is todetermine the relative adjustment of the two brakes which is shown byany oscillatory movement of the platform as the lever 36 is pulled.Should any such oscillatory movement occur during a test, the brakes ofthe pair of wheels are adjusted until repeated tests show no oscillatorymovement of the platform. Having accomplished equal adjustment of thebrakes, then there is to be determined the resistive effect of movementof the platform with respect to the braked wheels, to bring it up to thepoint to which the brakes of the particular machine are designed. Thisis accomplished by manipulation of the braking mechanism as a whole, bymechanics familiar with the same. When the desired resistive effect hasbeen achieved, as may be observed on the gauge rod 46, then the otherpair of wheels of the vehicle may be tested in like manner so that aftertest the driver of the vehicle may be assured that his brakes are evenlyand properly adjusted to give the full braking effect of the car asdesigned by its manufacturer.

The connection between the levers 33 and 36, as heretofore described, isthought to be sufficient for any useful purpose. It is to be understood,however, that other connections might be made between these levers toaccomplish the same purpose.

It will be observed that the test apparatus of the present invention isone which is so constructed as to be readily portable from place toplace or permanently fixed in position by any suitable means, e. g., bybolts through holes 58 in the base plate i. The apparatus very readilydetermines the degree of brake adjustment between both wheels of anypair of wheels of an automobile so that if maladjusted the brakes can beadjusted to provide the desired and designed braking effect, thusassuring maximum braking action of the vehicle so tested.

Arranging the scale i5 and the pointers l6 and H at the same end of theapparatus carrying the lever enables the test operator and the vehicledriver to very readily observe the condition of the brakes as soon asthe operator moves the lever 36 in direction to move the platformunderneath the braked wheels undergoing tests. The vehicle driver mayobserve the position of the pointers i6 and I! without leaving thevehicle, simply by looking out of his window. Preferably the surface ofthe platform A is slightly below the high points of the ramps to therebyform a pocket for the wheels on the platform.

The indicia 1, 2, 3, 4, etc. on the gauge rod 49 may represent 100, 200,300, 400 etc. pounds pressure, or resistance.

When the lever 36 is swung to rock the shaft 28, the roller 3| actsagainst the curved part 3i) of the hood 29, with cam action. Thecurvature of the part 30 is such as to enable the springs it to restorethe platform A and handle 35 to normal position, whenever the wheelbrakes are released.

The invention has been described herein more or less'precisely as todetails, yet it is to be understood that the invention is not to belimited thereby, as changes may be made in the arrangement andproportion of parts and equivalents may be substituted, withoutdeparting from the spirit and scope of the invention.

The invention is claimed as follows:

1. A brake testing apparatus including a single movable platform adaptedto receive both wheels of a pair of automobile wheels for testing thebrakes thereof, means supporting said platform for bodily movementsubstantially perpendicular to its length and also for oscillatablemovement about a central pivot, cooperating crank and cam means formoving said platform after said wheels are at rest thereon and thebrakes thereof applied, means for actuating said crank means, and meansfor indicating the amount of perpendicular and oscillatory movement ofsaid platform.

2. A brake testing apparatus including a single movable platform adaptedto receive a pair of automobile wheels thereon for testing the brakesthereof, means supporting said platform for bodily movementsubstantially perpendicular to its length and also for oscillatablemovement about a central pivot, cooperating crank and cam means formoving said platform after said wheels are at rest thereon and thebrakes thereof ap plied, means for actuating said crank means, said lastmentioned means being provided with means for visually representing theforce necessarily applied to said moving means to move said platformunder the conditions stated, and means for indicating the amount ofperpendicular and oscillatory movement of said platform.

3. A brake testing apparatus including a single movable platform adaptedto receive a pair of automobile wheels for testing the brakes thereof,means supporting said platform for bodily movement substantiallyperpendicular to its length and also for oscillatable movement about acentral pivot, cooperating crank and cam means for moving said platformafter said wheels are at rest thereon and the brakes thereof applied,means for actuating said crank means, said platform being movableperpendicularly to its length only when the brakes of said pair ofwheels are equally effective and oscillatable when the brakes of saidpair of wheels are unequally effective, and means for indicating theamount of perpendicular and oscillatory movement of said platform.

4. A brake testing apparatus including an elongated movable platformadapted to receive both wheels of a pair of wheels to be tested forrelative adjustment, a base member supporting said platform, anoscillatable shaft pivoted to said base member and extending therealongparallel to the length of the platform, a member having a curvilinearportion pivoted to said platform at substantially its mid-length, aroller carried by said shaft and adapted to contact said curvilinearportion with cam action to move said platform in one direction when saidshaft is rotated in one direction, means comprising relatively movablemembers to rotate said shaft in said one direction to move said platformwith respect to the pair of wheels thereon, spring means for moving saidplatform'in the opposite direction when said shaft is rotated in theopposite direction and to restore said shaft rotating means to normalposition, and a single force measuring device operable by the relativemovement of said shaft rotating means to register the resistance offeredto movement of said platform by the pair of wheels on it.

5. A brake testing apparatus including an elongated movable platformadapted to receive both wheels of a pair of wheels to be tested forrelative adjustment, a base member supporting said platform, said basesupporting said platform for bodilymovement of the platformperpendicular to its length and also for oscillatable movement about acentral point, a shaft pivoted to said base member and extendingtherealong parallel to the length of said platform, a member having acurvilinear portion pivoted to said platform at substantially itsmidlength, a roller carried by said shaft and adapted to contact saidcurvilinear portion with cam action to move said platform in onedirection when said shaft is rocked in one direction, means comprisingrelatively movable members to rock said shaft in said one direction tomovesaid platform with respect to the pair of wheels thereon, springmeans for moving said' platform and said shaft rocking means in theopposite direction and for restoring said shaft rocking means to normalposition, a single'force measuring device operable by the relativemovement by said shaft rocking means to register the resistance offeredto movement of said platform by the pair of wheels on it, and means forindicating the relative shifting of the ends of said platform as saidplatform is moved by its moving means.

6. In a brake testing apparatus, a base member, an elongated platform toreceive both wheels of a pair of wheels to be tested for relativeadjustment, mounted on said base member to move in a directionperpendicular to its length and also to oscillate about a central point;a shaft oscillatable in said base member and supported in parallelrelation to the length of said platform; an arm fixed to said shaft andsupporting a roller at its free end; a member pivotally secured to saidplatform at substantially its mid-length and having a curved faceagainst which said roller works with cam action, shaft rocking meansincluding two relatively movable members, one of which is fixed to saidshaft and the other of which is supported by said one member forswinging movement toward and away from said one member and constitutinga handle for rocking said shaft, the upper extremity of said handlemember adapted to be swung away from said one member when pressure is,applied thereto to move the platform; force indicating means comprisingparts carried by said two rela tively movable members, one partcomprising a bar having graduations on it and secured to said onemember, another part comprising a yoke pivoted to said other member andhaving its bridge portion apertured to receive and slide along said baras said members are relatively moved, the third part comprising a springsurrounding said bar and bearing at its ends against said one member andsaid yoke bridge and functioning to normally maintain said two membersin closely adjacent relationship; the movement of said handle member tomove said platform causing said yoke bridge to travel along said bartoward said one member to thereby permit observation to be made ofthe'resistance offered by said platform to moving it by comparing theposition of said yoke bridge with the graduations on said bar.

7. A brake testing apparatus including a single movable platform adaptedto receive both Wheels of a pair of automobile wheels for testing thebrakes thereof, means supporting said platform for bodily movementsubstantially perpendicular to its length and also for oscillatorymovement about a central pivot, means pivoted to said platform andconstituting a cam, a crank engag able with said cam for moving saidplatform in one direction after said wheels are at rest thereon and thebrakes of said wheels applied,'spring means for moving said platform inthe opposite direction, manually operable means including relativelymovable members for actuating said crank, a force applying measuringdevice operable by the relative movement of said members directed to theresistance offered to movement of said platform by the pair of brakedwheels on it, and means for indicating the amount of movement of saidplatform.

JACOB L. SI-EOYER.

